Li Yangyang, Li Tong, Shang Bin, Zhao Yang, Tao Xiuping, Peng Feng, Zou Xiaojun, Zhang Sixin
Key Laboratory of Energy Conservation and Waste Management in Agricultural Structures, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China.
Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, China.
Front Vet Sci. 2023 Jun 1;10:1178970. doi: 10.3389/fvets.2023.1178970. eCollection 2023.
The environment influences the sow's health and physiology during gestation. This study was conducted to evaluate indoor environmental parameters and physiological responses of early-gestation sows and investigate the possible methods for assessing the thermal environment in commercial houses.
A total of 20 early-gestation sows (commercial purebred Yorkshire) with an average body weight of 193.20 ± 3.62 kg were used for this study in winter, spring, summer, and autumn. The indoor environment parameters comprising dry-bulb temperature (T), relative humidity (RH), and carbon dioxide (CO) were recorded in 30-min intervals. Physiological parameters including heart rate (HR) and respiration rate (RR) of sows were also measured every 30 min. Wet-bulb temperature (T) was calculated using T, RH and atmospheric pressure was recorded at a nearby weather station.
The average indoor T and RH were 12.98 ± 2.03°C and 80.4 ± 6.4% in winter, 18.98 ± 2.68°C and 74.4 ± 9.0% in spring, 27.49 ± 2.05°C and 90.6 ± 6.4% in summer, and 17.10 ± 2.72°C and 64.5 ± 10.9% in autumn. A higher average concentration of CO was observed in winter (1,493 ± 578 mg/m) than in spring (1,299 ± 489 mg/m), autumn (1,269 ± 229 mg/m), and summer (702 ± 128 mg/m). Compared with the HR and RR in the optimum environment, high RH in the house led to a significant decrease in both HR and RR ( < 0.05). In addition, a significant decline in HR was also obtained at high temperatures ( < 0.05). A temperature humidity index (THI), THI = 0.82 × T + 0.18 × T, was determined for early-gestation sows, and the THI thresholds were 25.6 for HR. The variation in THI in summer showed that heat stress still occurred under the pad-fan cooling system.
This study demonstrated the critical significance of considering physiological responses of early-gestation sows in commercial houses and THI thresholds. We recommend that much more cooling measures should be taken for early-gestation sows in summer.
环境会影响妊娠期间母猪的健康和生理状况。本研究旨在评估妊娠早期母猪的室内环境参数和生理反应，并探讨评估商业猪舍热环境的可能方法。
本研究在冬季、春季、夏季和秋季共使用了20头妊娠早期母猪（商业纯种约克夏），平均体重为193.20±3.62千克。室内环境参数包括干球温度（T）、相对湿度（RH）和二氧化碳（CO），每隔30分钟记录一次。母猪的生理参数，包括心率（HR）和呼吸频率（RR），也每30分钟测量一次。湿球温度（T）通过T、RH计算得出，大气压力在附近气象站记录。
冬季室内平均T和RH分别为12.98±2.03°C和80.4±6.4%，春季为18.98±2.68°C和74.4±9.0%，夏季为27.49±2.05°C和90.6±6.4%，秋季为17.10±2.72°C和64.5±10.9%。冬季观察到的CO平均浓度（1,493±578毫克/立方米）高于春季（1,299±489毫克/立方米）、秋季（1,269±229毫克/立方米）和夏季（702±128毫克/立方米）。与最佳环境中的HR和RR相比，猪舍内高RH导致HR和RR均显著下降（<0.05）。此外，高温时HR也显著下降（<0.05）。为妊娠早期母猪确定了温度湿度指数（THI），THI = 0.82×T + 0.18×T，HR的THI阈值为25.6。夏季THI的变化表明，在湿帘-风机降温系统下仍会发生热应激。
本研究证明了在商业猪舍中考虑妊娠早期母猪生理反应和THI阈值的关键意义。我们建议在夏季应对妊娠早期母猪采取更多的降温措施。
